public static async Task <IReadOnlyList <GeocodeResult> > ReverseGeocodeAsync(MapPoint location, double maxDistance = 200)
{
await _geocoder.LoadAsync().ConfigureAwait(false);
var parameters = new ReverseGeocodeParameters()
{
MaxDistance = maxDistance
};
return(await _geocoder.ReverseGeocodeAsync(location, parameters).ConfigureAwait(false));
}
private async void MyMapView_GeoViewTapped(object sender, Esri.ArcGISRuntime.Xamarin.Forms.GeoViewInputEventArgs e)
{
try
{
// Clear existing callout and graphics.
MyMapView.DismissCallout();
MyMapView.GraphicsOverlays[0].Graphics.Clear();
// Add a graphic for the tapped point.
Graphic pinGraphic = await GraphicForPoint(e.Location);
MyMapView.GraphicsOverlays[0].Graphics.Add(pinGraphic);
// Reverse geocode to get addresses.
ReverseGeocodeParameters parameters = new ReverseGeocodeParameters();
parameters.ResultAttributeNames.Add("*");
parameters.MaxResults = 1;
IReadOnlyList <GeocodeResult> addresses = await _geocoder.ReverseGeocodeAsync(e.Location, parameters);
// Skip if there are no results.
if (!addresses.Any())
{
await Application.Current.MainPage.DisplayAlert("No results", "No results found.", "OK");
return;
}
// Get the first result.
GeocodeResult address = addresses.First();
// Use the address as the callout title.
string calloutTitle = address.Attributes["Street"].ToString();
string calloutDetail = address.Attributes["City"] + ", " + address.Attributes["State"] + " " + address.Attributes["ZIP"];
// Define the callout.
CalloutDefinition calloutBody = new CalloutDefinition(calloutTitle, calloutDetail);
// Show the callout on the map at the tapped location.
MyMapView.ShowCalloutForGeoElement(pinGraphic, e.Position, calloutBody);
}
catch (Exception ex)
{
await Application.Current.MainPage.DisplayAlert("Error", ex.ToString(), "OK");
}
}
/// <summary>
/// Reverse geocode au clic sur la carte
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
async void mapView1_GeoViewTapped(object sender, GeoViewInputEventArgs e)
{
// on set les paramètres du reverse geocode
ReverseGeocodeParameters geocodeParams = new ReverseGeocodeParameters();
geocodeParams.MaxDistance = 800;
geocodeParams.MaxResults = 10;
// on effectue le reverse geocode sur l'emplacement cliqué
IReadOnlyList <GeocodeResult> resultList = await myLocator.ReverseGeocodeAsync(e.Location, geocodeParams);
// si il y a un résultat, on affiche le premier
if (resultList.Count > 0)
{
reverseGeocodeLabel.Visibility = Visibility.Visible;
reverseGeocodeLabel.Content = "Magasin : " + resultList[0].Label;
}
else
{
reverseGeocodeLabel.Visibility = Visibility.Hidden;
}
}
private async Task UpdateGeocodeAsync(MapPoint location)
{
var layer = FindGraphicsOverlay("geocode");
if (layer.Graphics.Count == 0)
{
layer.Graphics.Add(new Graphic());
}
layer.Graphics[0].Geometry = location;
if (m_locatorTask == null)
{
m_locatorTask = await GetLocator();
}
GeocodeResult result = null;
try
{
var p = GeometryEngine.Project(location, m_locatorTask.LocatorInfo.SpatialReference) as MapPoint;
var param = new ReverseGeocodeParameters()
{
MaxDistance = 500
};
param.ResultAttributeNames.Add("*");
var results = await m_locatorTask.ReverseGeocodeAsync(p, param);
result = results?.FirstOrDefault();
}
catch { }
if (result != null)
{
ReverseGeocodeResult = string.Join("\n", result.Attributes.Values.ToArray());
}
else
{
ReverseGeocodeResult = "No result";
}
}
private async void MyMapView_GeoViewTapped(object sender, GeoViewInputEventArgs e)
{
try
{
// Clear existing callout and graphics.
MyMapView.DismissCallout();
MyMapView.GraphicsOverlays[0].Graphics.Clear();
// Add a graphic for the tapped point.
Graphic pinGraphic = await GraphicForPoint(e.Location);
MyMapView.GraphicsOverlays[0].Graphics.Add(pinGraphic);
// Reverse geocode to get addresses.
ReverseGeocodeParameters parameters = new ReverseGeocodeParameters();
parameters.ResultAttributeNames.Add("*");
parameters.MaxResults = 1;
IReadOnlyList <GeocodeResult> addresses = await _geocoder.ReverseGeocodeAsync(e.Location, parameters);
// Get the first result.
GeocodeResult address = addresses.First();
// Use the address as the callout title.
string calloutTitle = address.Attributes["Street"].ToString();
string calloutDetail = address.Attributes["City"] + ", " + address.Attributes["State"] + " " + address.Attributes["ZIP"];
// Define the callout.
CalloutDefinition calloutBody = new CalloutDefinition(calloutTitle, calloutDetail);
// Show the callout on the map at the tapped location.
MyMapView.ShowCalloutForGeoElement(pinGraphic, e.Position, calloutBody);
}
catch (Exception ex)
{
await new MessageDialog2(ex.ToString(), "Error").ShowAsync();
}
}
/// <summary>
/// Defines the method to be called when the command is invoked.
/// </summary>
/// <param name="parameter">Data used by the command. If the command does not require data to be passed, this object can be set to null.</param>
public void Execute(object parameter)
{
// The parameter should be an ESRI MapPoint.
var location = parameter as Esri.ArcGISRuntime.Geometry.MapPoint;
#region Sanity Check
if (location == null)
{
MessageBox.Show(
"A reverse geocode requires a location.",
"No Location",
MessageBoxButton.OK, MessageBoxImage.Error);
return;
}
#endregion
// We'll need access to the map view model.
var mapViewModel = MapViewModel.Current;
// Clear the list of reverse geocodes.
mapViewModel.ReverseGeocodeResults.Clear();
// We need the ESRI locator.
var locatorTask = MapViewModel.Current.MobileMapPackage.LocatorTask;
// Apply the Workaround, Part 1...
ReverseGeocodeParameters rgParams = new ReverseGeocodeParameters();
rgParams.MaxDistance = 10;
rgParams.OutputSpatialReference = mapViewModel.MapView.Map.SpatialReference;
rgParams.MaxResults = 5;
rgParams.ResultAttributeNames.Add("*");
// let's try a reverse geocode...
var results = Task.Run(async() =>
{
return(await locatorTask.ReverseGeocodeAsync(location, rgParams));
}).Result;
// Examine each of the results.
foreach (var result in results)
{
/**
* To those who want to troubleshoot... place a breakpoint
* here to examine the result returned by the LocatorTask.
*/
// Apply the Workaround, Part 2...
// (When we apply the parameters above, it seems that we get
// additional information in the Attributes collection. (The
// "Label" property still contains an empty string.)
var labelAsSeenInAttributes = string.Empty;
if (result.Attributes.Keys.Contains("Street"))
{
labelAsSeenInAttributes = result.Attributes["Street"] as string;
}
Console.WriteLine($"Label={result.Label}");
Console.WriteLine($"Score={result.Score}");
// Construct a label.
string label = string.IsNullOrWhiteSpace(labelAsSeenInAttributes) ?
"The label came back as an empty string. Why is that?" : labelAsSeenInAttributes;
// Create an instance of our own GeocodeResult to hold the
// values from ESRI's GeocodeResult.
Model.GeocodeResult resultNode = new Model.GeocodeResult(result);
// Place the reverse geocode results into the collection so
// they may be viewed.
mapViewModel.ReverseGeocodeResults.Add(
new ObjectNode($"Label={label}", resultNode));
}
}
